Synthesis, structure, and magnetic properties of SrLaMnSbO6:: A new B-Site ordered double perovskite

The synthesis, structural characterization, and magnetic property studies of SrLaMnSbO6 double perovskite oxide are reported. The crystal structure of SrLaMnSbO6 has been solved by powder,X-ray (PXD) and neutron diffraction (NPD) data in the monoclinic space group P2(1/n) (a = 5.6878(3) angstrom, b = 5.6990(2) angstrom, c = 8.0499(4) angstrom and beta = 89.98(2)degrees; 295 K, NPD data). The Mn and Sb atoms are nearly completely ordered over the B-site of the perovskite structure. The octahedral framework displays significant tilting distortion according to the Glazer's tilt system a(-)a(-)c(+). X-ray absorption near-edge spectroscopic (XAS) studies show the presence of Mn2+ and Sb5+ formal oxidation states. The magnetic susceptibility data of SrLaMnSbO6 indicate the presence of ferromagnetic correlations; the calculated effective paramagnetic moment, mu(calcd)= 5.92 mu(B) (for HS Mn2+(3d(5)), S = 5/2; as evidenced by XAS data) is in good agreement with the value obtained experimentally (mu(exp) = 5.70 mu(B))- Variable temperature neutron diffraction data show no evidence of structural transition down to 3.7 K. A long-range antiferromagnetic ordering is established at T-N = 8 K as evidenced by the magnetic susceptibility and specific heat measurements. The magnetic structure at 3.7 K is characterized by k = 0 propagation vector and m(1x) = -m(2x), m(1y) = m(2y) = 0, m(1z) = -m(2z) (m(x) = 1.26(7)mu(B), m(z) = 1.82(6) mu(B)) coupling of magnetic moments on the Mn-1 (1/2,0,0) and Mn-2 (0,1/2,1/2) atoms with the ordered magnetic moment of 2.21(4) mu(B).